1. Field of the Invention
The present invention relates to sorption systems where a sorbate is alternately adsorbed onto and desorbed from a sorbent and more particularly an improved sorber structure and method for making such a sorber.
2. Description of Related Art
In a sorption system, a first substance called a sorbate is alternately adsorbed (or absorbed) onto a second substance called a sorbent and then desorbed (or removed) from the sorbent. If the sorbate is adsorbed onto the sorbent, the system may be referred to as an adsorption system. If the sorbate is absorbed onto the sorbent, the system may be referred to as an absorption system. Sorption systems are often used to effectively compress the sorbate. For example, sorption systems may be used in refrigeration units in place of a compressor.
During an adsorption reaction, the sorbate which is drawn onto the sorbent forms a sorbate/sorbent compound. In an absorption system, essentially the same process occurs, except that the sorbate merely adheres to the sorbent rather than forming a compound with it. The specific sorbate and sorbent used in a particular sorption system may be selected to provide desired characteristics which depend upon the affinity of the sorbent and sorbate. It is not necessary to supply any energy to the system in order for the adsorption reaction to proceed.
During a desorption reaction, energy is supplied to the compound to break the bonds of the compound and separate the sorbate from the sorbent. This energy may be supplied by heating the sorbate/sorbent compound, or by supplying energy in the form of electromagnetic waves which can break the bonds between the sorbate and sorbent without heating them. Typically, during the adsorption reaction, the sorbate is a low pressure gas. During the desorption reaction, the volume of the sorbate which is separated from the sorbent is constrained, and a high-pressure sorbate gas is produced.
The absorption and desorption reactions normally take place in a sorber. The sorber typically comprises a housing in which a mass of sorbent is located. Ports are provided in the housing to allow the sorbate to enter and exit the housing so that it can be adsorbed onto and desorbed from the sorbent. The sorber is also configured to operate in conjunction with the desorption means (e.g., heater or electromagnetic wave generator.)
While it is typically advantageous to have a compact sorber design, it is also advantageous to provide the greatest possible surface area between the sorbate and sorbent. Typically, these competing considerations are optimized by providing a solid mass of sorbent and drilling a large number of holes into the sorbent to provide channels through which the sorbate can flow. Thus, the sorbate does not have to penetrate the outer layer of the sorbent mass in order to react with the inner layers. It can, however, be relatively costly to drill these holes in the sorbent.